This application is for a five-year extension of funding for the Pediatric Eye Disease Investigator Group (PEDIG) ? a clinical research network of pediatric eye care providers that was formed to conduct clinical research in strabismus, amblyopia, and other childhood eye disorders. The organization of the PEDIG network enhances efficiency and quality while reducing costs by having a single infrastructure with the ability to conduct concurrent and consecutive studies. Since its inception in 1997, PEDIG has conducted 41 randomized clinical trials or prospective observational studies including 23 in amblyopia, 9 in strabismus, 3 in nasolacrimal duct obstruction, 2 in myopia/hyperopia, 1 in retinopathy of prematurity, 1 in pediatric optic neuritis, 1 in pediatric cataract surgery, 1 in corneal thickness, as well as several pilot studies. Each study has contributed significantly to the evidence-base for pediatric eye care and has changed the way eye care is practiced by addressing common and/or sight-threatening conditions faced by children. The proposed studies in the current application would continue to advance the field in an evidence-based direction, improving care and quality of life for children. By the time the funding requested in this application would begin, 2 new protocols will have started ? a randomized trial to evaluate laser refractive surgery for residual anisometropic amblyopia and a randomized trial to evaluate low dose atropine drops for slowing myopia progression. Despite PEDIG's numerous accomplishments, many important clinical questions and controversies in pediatric eye care and strabismus remain. PEDIG has developed, or will be developing clinical trials to address many of these questions including: (1) risk factors for non-response to amblyopia treatment, using occlusion dose monitors to measure actual patch wearing time, (2) the utility of binocular treatment of amblyopia in older children and adults, (3) the effect of bifocal treatment for amblyopia, (4) the effect of bifocal versus single vision lenses for high AC/A esotropia, (5) the effect of partial versus full hyperopic correction in childhood esotropia, (6) whether adjustable sutures have advantages over non-adjustable sutures for strabismus surgery, and (7) the optimum dose of bevacizumab and optimum follow-up schedule for infants with retinopathy of prematurity. Specific aims for the next 5-year funding period are to: (1) complete the 7 protocols that are expected to be in progress at the time funding begins, (2) initiate 10 new protocols for common pediatric eye disorders and strabismus where the current management does not have an evidence-based rationale, (3) continue to expand the PEDIG network by soliciting new sites and encouraging involvement of young investigators, (4) continue to educate eye care providers and research coordinators on the principles of clinical trials and good research practices, (5) train eye care providers to be leaders in clinical trials and research, (6) develop new methods and outcome measures needed to conduct future clinical trials, and (7) continue to broadly disseminate the results of PEDIG studies to the eye care community through publications, presentations, and courses at national meetings.